TPS and Entry Technologies for Future Outer Planet Exploration

The lack of knowledge about the Ice Giants (Voyager being the only probe to briefly visit them) and literally narrow window of planetary alignment for pragmatic missions to the Ice Giants, make them high priority targets in the next decade. The purpose of this white paper is to provide an overview to the NRC Decadal Survey on thermal protection system (TPS) technologies required for future Outer Planet exploration missions. A prime conclusion is that several of the most significant recommendations made during the last decadal survey were addressed positioning the TPS community to better support missions to the Outer Planets. These include maturation of the Heatshield for Extreme Entry Environment Technology (HEEET) to TRL 6 as replacement for Carbon Phenolic (that requires requalification itself), TPS test facility upgrades, and design tool improvements. These new materials and test methods are enabling for Outer Planet missions. However, there are limitations in the HEEET technology and available ground based test facilities that could become mission constraints depending on the science objectives. This white paper discusses opportunities to mitigate those constraints. In addition, if a mission is not scheduled in the near future, these new developments are at risk of becoming unavailable. Therefore, we recommend that NASA invest in a cross-cutting technology program that focuses on sustainment of relevant TPS materials, entry systems, test facilities, design tools, and flight instrumentation.